How to get started?

I would run a search on this but I've got too many questions. I'm extremely interested in starting up on the stand-up. I've been playing electric now for a few years and I want to switch over, though not completely. So the questions I have about starting are as follows:
Learning:
I started playing electric and just picking up how to play and what not as I went along. But I picked up a bunch of bad habits and after studying under Adam Nitti quickly realized how many bad habits I had to break. So if I'm starting should immediately get into lessons?
Buying:
Also, I bought my first bass by just walking in a store uninformed and picked one up. I soon went thru three basses in about one year and after learning and knowing what I needed to know ended up with my deluxe p-bass. So what's the best advice for someone who has no idea about the difference in stand up basses? Is there a company that makes good starter basses? should I buy used first? or start off with a really nice bass that I won't need to replace?

1. Get a teacher first. You are right on the with the "no bad habits" concept.

2. Refer to the above when selecting a bass. One thought is to rent first. A fine idea, but I'm not a big supporter of renting anything. So, IMO, if you have the $$$ to let float around, buy a decent quality, used bass. If you decide this isn't for you, just sell it. You should be able to get all or most of your money back as long as it didn't take any abuse and you didn't overpay in the first place.

In either case, work with your teacher in the selection process. At this point, you don't even really know what you want.